Heathrow has offered to spend £450 million more on protecting homes from aircraft noise if it wins the green light for a third runway.

The airport estimates that more than £700 million could be spent through the new insulation package, an increase of over £450 million from that previously offered in its May 2014 submission to the Airports Commission.

The new figure represents an increase of more than £610 million from its previous proposals for a third runway.

The newly-proposed scheme would cover a zone based on a 55 decibel noise contour, the preferred measure of noise used by the European Union and the mayor of London, Heathrow said.

This noise insulation goes “above and beyond” UK policy requirements, expands on Heathrow’s previous proposals and is comparable to those offered by other European hub airports.

The measure came ahead of today’s deadline for public consultation by the commission into airport expansion in the south-east.

More than 160,000 homes could be eligible for insulation in areas from Windsor in the west to Richmond in the east.

Over 35,000 homes in Hounslow would be eligible for full costs of the noise insulation package, with all homes in Heston and Cranford eligible. Homes within the towns and villages of Wraysbury, Datchet, Sipson, Harmondsworth, Harlington, Colnbrook, Brands Hill and Stanwell Moor would also be covered by the scheme.

Properties in the designated zone closest to the airport with higher levels of noise stand to have the full costs of their noise insulation covered by the airport. In addition, up to £3,000 in noise insulation would be offered to homes further away from the airport

The scheme is based on two newly designated insulation zones, and residents would be eligible regardless of whether they experience noise under existing flight paths or will be newly affected by noise from a new runway.

A third party assessment, free of cost to homeowners, would be made to determine the extent of each home’s needs within the eligible insulation zones.

The insulation package could include:

Acoustic double glazing in windows

Ceiling overboarding in bedrooms

Loft insulation and ventilation

Heathrow chief executive John Holland-Kaye said: “We designed the new approach to expanding Heathrow to minimise noise to local residents, but we also need to mitigate the impact on those who are still affected.

“Today’s announcement does that, and is based on the feedback we have received from local residents over the last few months; it will reduce the impact of noise, and treat local people fairly.

“Now we want to work with local communities to ensure that the opportunities from expansion – up to 40,000 new skilled jobs at Heathrow, 10,000 apprenticeships, tackling youth unemployment – benefit those who are most affected by expansion.”

The offer is subject to government policy support and regulatory approval by the Civil Aviation Authority.

But Gatwick chief executive Stewart Wingate said the Heathrow commitments did not go far enough.

“Heathrow should follow Gatwick’s lead and offer to pay the council tax of people most affected if it’s serious about compensating people for noise,” he said. “Heathrow can’t afford to do that of course as it already impacts more people than all the major European airports combined.

“Expand Heathrow and 320,000 new people will be affected by noise – a population the size of Coventry – compared to 18,000 people at Gatwick.

“The government can choose a third runway at Heathrow but, as Sir Roy McNulty chairman of Gatwick, said at the weekend there will be ‘all hell to pay’ if they do. This has to be a decision that carefully balances the economic benefits with the environmental impact. Gatwick is the obvious answer.”

A cross-party group of MPs and campaigners from across London will hand in a letter to Number 10 Downing Street today (Tuesday) urging the prime minister to stick to his promise made before the 2010 general election to not expand Heathrow.